1. Field of the Invention
The invention relates to a system comprising cultivating tables as well as an irrigation device for supplying a liquid medium to cultivation products being cultivated on the cultivating tables. The liquid medium is in particular water, which may or may not contain nutrients for the cultivation products, whilst the cultivation products themselves are usually potted plants or the like. It is noted that the invention is not limited to a specific irrigation method. Thus, the irrigation device may operate according to a so-called ebb-and-flow system, in which the cultivating tables are cyclically inundated to a certain level during a flow period and allowed to run completely dry during an ebb period so as to prevent in particular root rot and fungus occurring at the bottom side of the cultivation products. According to another irrigation method, the water is applied to the cultivation products directly or in drops above the cultivating tables.
2. Description of the Related Art
Such a system operating according to the aforesaid ebb-and-flow system, comprising ten to twenty cultivating tables, for example, is known from U.S. Pat. No. 5,355,618 (Pedersen). In this known system, water is supplied as the irrigation medium in a central inlet pipe under the cultivating tables, in which a magnetically actuated main valve can open the central supply of water during a flow period and shut it off during an ebb period.
One drawback of the system that is known from the aforesaid US patent publication is the following. Nowadays it is usual to position cultivating tables side-by-side (i.e. without aisles) in a greenhouse in order to optimally utilize the space in said greenhouse. The cultivating tables roll on rails installed in the greenhouse in that case. Thus it is possible to move a cultivating table (via an automated system) to an adjoining space, where a manual operation (for example pruning or harvesting) of the cultivation products being cultivated on said cultivating table is to be carried out. Staff present in said adjoining space are thus not exposed to high temperatures and/or polluted air in the greenhouse. The known system is not suitable for this kind of use, since it concern a system of stationary cultivating tables.